Player for YouTube is a third-party YouTube browser with log-in and upload features that, while well made, don't offer a lot more than the native YouTube app does. This is not necessarily a bad thing, especially if you are looking for a solid third-party app that doesn't have all of the pushy bells and whistles of the official Google app -- but it won't be a good fit for everyone.
When you open Player for YouTube for the first time, you'll be greeted with familiar categories showing top videos, trending videos, top favorites, etc. Oddly, though, most of these in our tests were old but popular videos like "Charlie Bit my Finger." Very few of the top-rated videos were very recent, even after logging into an account. You can do this from the log-in screen and there is an option to upload videos from directly in the app, which is a nice touch. Combined with the playlist and favorite list management tab, Player for YouTube strives to streamline browsing and accessibility of the videos here.
If you are unhappy with the core YouTube app offered by Google or if you want a new third-party option for your iPhone, Player for YouTube is a decent app. The interface is fairly basic and the default filters seem to be pulling a lot of older videos, but everything else works well, and is generally very fast -- an important factor for any app when surfing YouTube.